Utility companies see variable demand for electricity around the year. There are certain intervals of peak demand, usually during summer afternoons and other times when the demand is above average. During periods of peak demand, utility companies provide incentives to consumers to reduce their electricity demand (via Demand Response Requests). Consumers on their part, take steps to reduce their electricity consumption during these time intervals (also called as Demand Response Events). The Demand Response Request either specifies an absolute reduction in electricity consumption (load) or a relative reduction or specifies an enhanced per-unit unit price during the Event, which the consumer can translate into an absolute load reduction number.
Today's techniques are static in nature and are pre-configured for a fixed behavior. For example, in a department store every other light fixture might be turned off or the thermostat temperature set points changed during a Demand Response Event. These measures do not account for the current occupancy of the store and might impact sales. It would be a lot more desirable to keep the occupied aisles full bright and dim unoccupied spaces. Similarly based on the occupancy of the store the amount of air changes per hour might be adjusted enabling untapped HVAC savings.
A significant part of the electricity consumption for any consumer is due to the lighting loads. Hence consumers allocate a part of the load reduction during Demand Response Events to reduction of lighting loads. Electrical lighting is virtually a necessity in any work environment, and reducing the lighting load either by dimming or switching off lights can impact the productivity of the workers and the usability of the space. Lighting loads are ubiquitous in the built environment. All areas at a building site are not equally affected by changing light levels. For example, work being done in areas such as laboratories or executive rooms is likely to be more important and critical to the establishment than work being done in areas such as break rooms or corridors. Secondly, minimum illumination requirements are not uniform across all areas. Safety requirements often dictate a minimum illumination level in certain areas though not in others. The differing minimum and average illumination requirements in various areas mean that any potential lighting load reduction during a Demand Response Event cannot be uniform across all lighting loads. The load reduction in critical areas needs to be less as compared to the load reduction in non-critical areas.
Similarly, during Demand Response Events a part of the overall load reduction is obtained from other electricity consuming devices such as HVAC equipment, computing equipment and so on. Much like lighting, not all HVAC equipment or computing equipment is treated equally when it comes to load reduction. Some of the equipment may be more important for the organization goals, and proportionally lesser load reduction needs to be obtained from such equipment.
It is desirable to have methods, systems and apparatuses for distribution of an overall load reduction in a building with special emphasis on individual lighting loads.